摘要：In detailed aerodynamic design optimization,a large number of design variables in geometry parameterization are required to provide sufficient flexibility and obtain the potential optimum ***,with the increasing number of design variables,it becomes difficult to maintain the smoothness on the surface which consequently makes the optimization process progressively *** this paper,smoothing methods based on B-spline functions are studied to improve the smoothness and design *** wavelet smoothing method and the least square smoothing method are developed through coordinate transformation in a linear space constructed by B-spline basis *** these two methods,smoothing is achieved by a mapping from the linear space to itself such that the design space remains unchanged.A design example is presented where aerodynamic optimization of a supercritical airfoil is conducted with smoothing methods included in the optimization *** results from the design example confirm that these two smoothing methods can greatly improve quality and efficiency compared with the existing conventional non-smoothing method.

摘要：During airdrop of heavy load, the flight parameters vary continuously as the load moves in the hold, and change suddenly when the load drops out. This process deteriorates the flight quality and control characteristic as the load becomes heavier. Based on the simplified airdrop flight equations, the backstepping and switch control methods are developed to tackle the flight state holding and disturbance/uncertainty （such as large-scale flight condition, pilot manipulation error, system measure delay, etc.） attenuation problem in this paper. Moreover, these methods can be used as a reference for pilot manipulating during airdrop. With the backstepping theory, an adaptive controller is synthesized moves in the hold, and then a coordinated switch control method is for the purpose of stabilizing the transport when the load used to control the aircraft when the condition jumps from the existence of load at the rear of fuselage to no load in the fuselage. Simulation results show that the proposed controllers not only provide effective state holding during airdrop, but also achieve robust performance within wide flight conditions.

摘要：吸气式高超声速飞行器(air-breathing hypersonic vehicle,AHV)的飞行动力学模型具有高度非线性与多变量耦合等特性,且受到内部不确定性与外部干扰的综合影响,因此需要具有强鲁棒性与高精度的控制器。本文介绍了一种改进的基于随机鲁棒性分析的线性二次调节器(linear-quadratic regulator,LQR)设计方法,用于AHV的纵向飞行控制器设计。首先,应用输入输出反馈线性化技术设计LQR控制器。其次,基于系统参数的不确定性,将系统鲁棒性表征为满足稳定性与设计指标要求的概率,并构建系统鲁棒性与LQR参数之间的映射关系。为了实现系统鲁棒性最大化的目标,提出一种全新的混合粒子群优化算法对LQR的控制参数进行寻优计算。在优化迭代的过程中,使用切诺夫边界理论确定蒙特卡洛估计的随机样本量。最后,仿真结果表明该优化算法可以高效地获取满足设计要求的LQR控制参数最优解。

摘要：The pylon structure of an airplane is very complex, and its high-fidelity analysis is quite time-consuming. If posterior preference optimization algorithm is used to solve this problem, the huge time consumption will be unacceptable in engineering practice due to the large amount of evaluation needed for the algorithm. So, a new interactive optimization algorithm-interactive multi-objective particle swarm optimization （IMOPSO） is presented. IMOPSO is efficient, simple and operable. The decision-maker can expediently determine the accurate preference in IMOPSO. IMOPSO is used to perform the pylon structure optimization design of an airplane, and a satisfactory design is achieved after only 12 generations of IMOPSO evolutions. Compared with original design, the maximum displacement of the satisfactory design is reduced, and the mass of the satisfactory design is decreased for 22%.

摘要：Solid propellant air-turbo-rocket(SPATR) is an air-breathing propulsion system.A numerical model of performance and characteristics analysis for SPATR was presented and the corresponding computer program was written according to the operation characteristics of *** influence on the SPATR performance at design point caused by the gas generator exit parameters and compressor pressure ratio had been computed and analyzed in *** off-design performance of SPATR at sea level and high altitude had also been *** performance of thrust and specific impulse for SPATR with different solid propellant had been compared at off-design points,and the off-design performance comparison had been made between fuel-rich and *** computation results indicated that SPATR operates within wide range of Mach number(0~3) and altitude(0~12 km),and SPATR possesses high specific thrust(1 200 N/(kg/s)) and high specific impulse(7 000 N/(kg/s)) when fuel-air ratio of combustor equals fuel-air ratio.

摘要：In this paper a numerical investigation has been presented on the stall mechanism of a highly loaded Single Stage Low Speed Fan designed for the research test facility to be installed at North Western Polytechnic university (NWPU) Xi’an, China. The results presented are for the design point, near stall and just stall operating conditions at design speed. Design point studies have been found to be an indicative of stall area. Unsteady method of domain scaling has been used to compute the results at near stall and just stall conditions. It has been found that unlike the conventional tip leakage flow of the rotor, stator hub section is mainly responsible for the stall of the fan. The flow mechanism has been discussed with correlation to the design variables and previous investigations. Commercial CFD code NUMECA FINE/Turbo has been used for computations; results have been compared with results obtained from commercial CFD code ANSYS-CFX. The loss prediction of latter code is conservative than the former. The stall mechanism predicted by both codes is analogous.

摘要：Currently,osteochondral(OC)tissue engineering has become a potential treatment strategy in repairing chondral lesions and early osteoarthritis due to the limited self-healing ability of ***,it is still challenging to ensure the integrity,physiological function and regeneration ability of stratified OC scaffolds in clinical *** OC scaffolds are attractive to overcome the above problems because of their similar biological and mechanical properties with native OC *** a consequence,the researches on biomimetic design to achieve the tissue function of each layer,and additive manufacture(AM)to accomplish composition switch and ultrastructure of personalized OC scaffolds have made a remarkable *** this review,the design methods of biomaterial and structure as well as computer-aided design,and performance prediction of biopolymer-based OC scaffolds are presented;then,the characteristics and limitations of AM technologies and the integrated manufacture schemes in OC tissue engineering are summarized;finally,the novel biomaterials and techniques and the inevitable trends of multifunctional bio-manufacturing system are discussed for further optimizing production of tissue engineering OC scaffolds.

摘要：To satisfy the mechanical and biological requirement of porous bone substitutes, porous Ti with two different pore sizes designed in advance was fabricated by the space-holder sintering process. Mechanical properties of the porous Ti were explored via room temperature compressive~tests. The pore sizes and shapes are uniform throughout the specimens with porosities ranging from 36% to 63%. The compression strength and the elastic modulus are in the range from 94.05 to 468.57 MPa and 2.662 to 18 GPa, respectively. It is worth noting that the relationship between the compressive strength and the porosities is completely linear relation beyond the effect of pore size distributions on the mechanical properties. The value of the constant C achieved from the Gibson-Ashby model suggests that the pore sizes affect the yield strength of the porous Ti and the values of density exponent ( n ) for porous Ti with two different pore sizes are higher than 2, which suggests that the deformation mode of the porous Ti with a porosity ranging from 36% to 63% is mainly buckling of the cell struts.

摘要：Based on the microscopic elasticity theory and microscopic diffusion equation, the precipitation progress of the binary alloys including coherent strain energy was studied. The results show that coherent strain has obvious effect on the coherent two-phase morphology and precipitation mechanism. With the increase of coherent strain energy, the particles shape changes from the randomly distributed equiaxed particels to elliptical precipitate shapes,their arrangement orientation increases; in the late stage of precipitation, the particle arrangement presents obvious directionality along the [10]and[01]directions, and the precipitation mechanism of alloy changes from typical spinodal decomposition mechanism to the mixture process which possesses the characteristics of both non-classical nucleation growth and spinodal decomposition mechanisms.

摘要：一个新微可编程的燃烧栅栏(PBG ) 被设计，制作并且描绘了使用二层的多晶硅表面 micromachining 过程。介绍的 PBG 在结构简单并且有为一个宽波长范围的连续光谱的调节的能力。最大化运作的燃烧角度，当为栅栏条板的关键部件，和它的高度接近了空气差距，酒窝结构被采用。由大小，发达 PBG 样品能到达 5.19 的一个最大的燃烧角度 ???????? 瘠瑡牥瑩吗？